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This an the next image are from:
Rayment E. Moxley, Mark D. Adley and Bob Rohani (Structures Laboratory, US Army Waterways Experiment Station, Vicksburg, MS, USA),
“Impact of thin-walled projectiles with concrete targets”, Shock and Vibration, Vol. 2, No. 5, pp 355-364, 1995
ABSTRACT: An experimental program to determine the response of thin-walled steel projectiles to the impact with concrete targets was recently conducted. The projectiles were fired against41-MPa concrete targets at an impact velocity of 290 m/s. This article contains an outline of the experimental program, an examination of the results of a typical test, and predictions of projectile deformation by classical shell theory and computational simulation. Classical shell analysis of the projectile indicated that the predicted impact loads would result in circumferential buckling. A computational simulation of a test was conducted with an impact/penetration model created by linking a rigid-body penetration trajectory code with a general-purpose finite element code. Scientific visualization of the resulting data revealed that circumferential buckling was induced by the impact conditions considered.
BACKGROUND: Investigations into the survivability of hardened structures due to impact by conventional air-delivered munitions such as air-delivered bombs, have focused on defeating the bomb by casing failure. A traditional method of hardening structures against attack by aerial bombs is to place a burster slab over the structure. The burster slab is designed to detonate or break up contact-fused bombs and withstand penetration and blast effect of tail-fused bombs (Department of the Army, 1986). A concrete burster slab design was recently evaluated to investigate the effect of construction joints on the penetration resistance of the slab. Subscale thin-walled projectiles (simulating general purpose bombs) were fired into sections of the burster slab within a velocity range of 276-298 m/s. The penetration experiments were conducted at the US Army Engineer Waterways Experiment Station (WES) Projectile Penetration Research Facility which accommodates large targets constructed under laboratory-controlled conditions (Frew et al., 1993). All projectiles broke up after partial penetration into the slab. This article presents a discussion of the test results, an analysis of the structural response of the projectile using classical shell theory, and an ABAQUS finite element simulation of the test (ABAQUS is available under license from Hibbitt, Karlsson, and Sorensen, Inc., 1989a,1989b, 1989c).
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